When James MacKenzie of Allangrange died without issue in 1907, the line of chiefs of Clan Choinnich appeared to have died out, and the 20th century was to see the sale of most of the ancestral lands of the main MacKenzie families. However, interest in the history of the clan continued to grow. In the middle of the century it attracted the attention of academic historians like Rev. William Matheson of Edinburgh University, and towards the end of the century of young scholars like Aonghus MacCoinnich of Glasgow University. The question of the chiefship was revived by the Inverness lawyer & genealogist Duncan Warrand, whose "Some MacKenzie Pedigrees" (published in 1965) was an important corrective to the genealogical histories published in the previous century. A particularly keen amateur historian of the clan was the heir to the Earldom of Cromarty/Cromartie (which had been revived in the 1860s), and in 1979 Roderick Blunt-Mackenzie, 4th Earl of Cromartie, was recognised by the Lord Lyon as Chief of Clann Choinnich - or as he's known by all MacKenzies, "Cabarfeidh". See Cromartie.

Though Tarbat House was sold in the 1960s, the Cromartie family retained their 16th century home at Castle Leod. With the recognition of the Earl as chief it became the seat of the clan, and the subject of an international appeal to raise money for its repair and restoration - a process helped by the creation of new Clan MacKenzie Societies around the world. In the USA, MacKenzies coming together in 1974 at the Grandfather Mountain Highland Games started working towards the creation of an American society. A society was founded in Australia in 1984, and a Canadian Chapter of the Clan MacKenzie Society of the Americas emerged in 1988. Five years later a new Scottish society was formed - which has since come to be known as the Clan MacKenzie Society of Scotland & the UK - and in 1995 it hosted the first Clan MacKenzie Parliament at an International Gathering in Strathpeffer. It was formally opened by John Mackenzie the 5th Earl of Cromartie, who had succeeded his father in 1990, after the Seanchaidh had recited his pedigree in accordance with the old traditions of Highland clanship. See Societies.